cc: Move TryScroll from LayerImpl to LayerTreeHostImpl

cc/proto/property_tree.proto

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 syntax = "proto2";
 
 import "rectf.proto";
 import "scroll_offset.proto";
 import "size.proto";
 import "transform.proto";
@@ skipping 84 matching lines @@
 // Proto for struct ScrollNodeData
 message ScrollNodeData {
   optional bool scrollable = 1;
   optional int32 main_thread_scrolling_reasons = 2;
   optional bool contains_non_fast_scrollable_region = 3;
   optional Size scroll_clip_layer_bounds = 4;
   optional Size bounds = 5;
   optional bool max_scroll_offset_affected_by_page_scale = 6;
   optional bool is_inner_viewport_scroll_layer = 7;
   optional bool is_outer_viewport_scroll_layer = 8;
+  optional int64 transform_id = 9;
 }
 
 // This defines the proto used for all types of struct TreeNode.
 message TreeNode {
   // The following fields are the base TreeNode properties. This list
   // corresponds to the data members from struct TreeNode.
   optional int64 id = 1;
   optional int64 parent_id = 2;
   optional int64 owner_id = 3;
 
@@ skipping 49 matching lines @@
   optional PropertyTree scroll_tree = 7;
 
   optional bool needs_rebuild = 4;
   optional bool non_root_surfaces_enabled = 5;
   optional int64 sequence_number = 6;
 
   optional Vector2dF inner_viewport_container_bounds_delta = 8;
   optional Vector2dF outer_viewport_container_bounds_delta = 9;
   optional Vector2dF inner_viewport_scroll_bounds_delta = 10;
 }